The present invention relates to a process for releasing fragrance in the presence of absorbent materials. More particularly, the process includes providing a delivery vehicle containing an enrobement material, a fragrance, and a fixative, which are then combined with a moisture and/or malodor absorber to convey a fragrance to the atmosphere, and to provide an absorbent for moisture and/or malodors.
Absorbent materials are well known in the art to absorb moisture or malodors in products such as sanitary products, diapers, cat litter, air fresheners, and the like. Often mixtures of absorbents are used to obtain optimum performance with good odor control. For example, Brewer, U.S. Pat. No. 3,789,797 discloses an animal litter prepared from alfalfa, bentonite, and a binder for absorbing and neutralizing the odors of animal waste matter. Dickey, U.S. Pat. No. 4,519,340 discloses an absorbent composition for absorbing animal waste made from a mixture of natural absorbents such as corn stalks, wood shavings, hulls of cereal grain, and other components. Goodwin et al., U.S. Pat. No. 4,571,389 discloses an absorbent based on rice hull ash with multiabsorbent purposes. Karapasha et al., U.S. Pat. No. 5,306,487 discloses a particle composition for use with diapers and the like, which is based upon a high absorbent gelling material combined with odor-controlling materials such as zeolites, for example molecular sieve zeolites marketed under the trade name of ABSCENTS (Union Carbide Corporation and UOP), and activated carbon. Guarracino et al., U.S. Pat. No. 6,096,299 discloses an odor control material based upon a zeolite with a specific particle size. Neckernann, U.S. Pat. No. 3,816,577 discloses a cherry pit extract for deodorizing animal waste.
In absorbent products, it is also desirable to release a deodorant or a masking scent to maintain a pleasant smelling environment. In such products, fragrances are normally added directly to a particulate material or pre-mixed into an absorbent carrier. It is recognized that absorbers, especially those with high odor absorption capacity, may reduce the impact of fragrances if the fragrance is added directly to the absorber or premixed with, e.g., a zeolite.
For example, Kiebke, U.S. Pat. Nos. 5,216,980, and 5,361,719 each disclose a composition in which the fragrance carrier is ground corncob. Brewer, U.S. Pat. No. 3,921,581 discloses a moisture sensitive fragrance releasing solid containing powdered solids, such as finely ground alfalfa and sawdust with pre-gelatinized starch as the moisture sensitive ingredient. Miller, U.S. Pat. No. 3,675,625 discloses that when fragrance is added to absorbent material, it is no longer easily perceived until desorbed by moisture. In this composition, moisture release overcomes some of the problems but because the bulk absorber is hydrophilic, fragrance release is of short duration and malodors may be perceived if the absorber has only moderate odor absorbing capacity. The use of a high malodor absorbent capacity powder in such a system reduces both the malodor and the scent. For example, Paul, U.S. Pat. No. 5,782,409 discloses an air freshening and deodorizing system in which the fragrance and the malodor absorber are kept physically separated to overcome this problem.
In sum, heretofore when a fragrance was combined in a malodor/moisture absorbing system, an undesirable loss of fragrance or reduction in fragrance longevity was observed. This effect was even more pronounced when a super absorbent material was combined with such systems. As noted above, to combat this problem, the fragrance component was maintained separately from the absorbent material. The requirement for such separation, however, was inconvenient, uneconomical, and inefficient.
Thus, a need exists for a process for absorbing moisture and/or malodor, and providing a scent to the surrounding ambience (air) that avoids the problems of the prior art summarized above. Preferably, the process should be easy to use by the consumer, and utilize a composition that does not require that the fragrance and the absorbent material, e.g., moisture and/or malodor absorber, be physically separated.
One embodiment of the invention is a process for absorbing moisture and/or malodor, and providing a fragrance to the surrounding ambience. This process includes (a) providing a delivery vehicle containing an enrobement material, a fragrance, and a fixative, wherein the delivery vehicle is a free flowing powder; (b) combining the delivery vehicle with an absorbent material to form a mixture; and (c) contacting the mixture of (a) and (b) with a moisture and/or a malodor source.
Another embodiment of the invention is a fragranced delivery vehicle. This fragranced delivery vehicle includes a fragrance composition dispersed in a fixative and an enrobement material, wherein the fragrance composition, fixative, and enrobement material, when combined, form a free flowing powder.
Another embodiment of the invention is a process for providing a fragrance and moisture and/or malodor absorbing capacity to a substrate. This process includes (a) providing a free flowing powder containing a fragrance composition, a fixative, an enrobement material, and an absorbent material; and (b) contacting the free flowing powder with the substrate.
Another embodiment of the invention is a composition for absorbing moisture and/or malodor and imparting a fragrance to a surrounding environment. This composition includes from about 30% (wt) to about 98% (wt) of an absorbent material; from about 1% (wt) to about 20% (wt) of a delivery vehicle, wherein the delivery vehicle includes, in a free flowing powder, a fragrance, a fixative, and an enrobement material; and 0% to 50% (wt) of fillers and binders.
A further embodiment of the invention is a fragrancing and moisture and/or malodor suppression system. This system includes (a) a free flowing powder containing a fragrance composition, a fixative, and an enrobement material combined with an absorbent material; (b) a housing means for housing the free flowing powder including the absorbent material; and (c) a vapor permeable outer material disposed about the housing means, wherein moisture and malodor from a surrounding environment may diffuse through the outer material and into the free flowing powder and fragrance from the free flowing powder may diffuse through the outer material into the surrounding environment.